U.S. patent application number 12/820330 was filed with the patent office on 2011-01-27 for noncontact power feed system, noncontact relay apparatus, noncontact power reception apparatus, and noncontact power feed method.
This patent application is currently assigned to Sony Corporation. Invention is credited to Kenichi FUJIMAKI, Hirotsugu WADA.
Application Number | 20110018359 12/820330 |
Document ID | / |
Family ID | 43496645 |
Filed Date | 2011-01-27 |
United States Patent
Application |
20110018359 |
Kind Code |
A1 |
WADA; Hirotsugu ; et
al. |
January 27, 2011 |
NONCONTACT POWER FEED SYSTEM, NONCONTACT RELAY APPARATUS,
NONCONTACT POWER RECEPTION APPARATUS, AND NONCONTACT POWER FEED
METHOD
Abstract
A noncontact power feed system includes: a noncontact power feed
apparatus including a power feed resonance device to supply
alternate-current power to an electronic apparatus by resonance in
a noncontact manner, and an alternate-current power source section
to generate the alternate-current power and supply it to the power
feed resonance device; a noncontact relay apparatus including a
relay resonance device to receive the alternate-current power and
relay it to another electronic apparatus by resonance in a
noncontact manner, a relay-side rectifier circuit to form
direct-current power for output, and a movement means for moving
the noncontact relay apparatus by the direct-current power; and at
least one noncontact power reception apparatus including a power
reception resonance device to receive the alternate-current power
by magnetic field resonance in a noncontact manner, a
power-reception-side rectifier circuit to form direct-current power
for output, and a load means driven by the direct-current
power.
Inventors: |
WADA; Hirotsugu; (Kanagawa,
JP) ; FUJIMAKI; Kenichi; (Kanagawa, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, L.L.P.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Sony Corporation
Tokyo
JP
|
Family ID: |
43496645 |
Appl. No.: |
12/820330 |
Filed: |
June 22, 2010 |
Current U.S.
Class: |
307/104 |
Current CPC
Class: |
B60L 53/122 20190201;
H02J 50/12 20160201; H02J 50/40 20160201; Y02T 10/70 20130101; Y02T
90/14 20130101; Y02T 10/7072 20130101; H02J 5/005 20130101; H02J
7/025 20130101; Y02T 90/12 20130101; B60L 53/126 20190201 |
Class at
Publication: |
307/104 |
International
Class: |
H02J 17/00 20060101
H02J017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 23, 2009 |
JP |
2009-171797 |
Claims
1. A noncontact power feed system, comprising: a noncontact power
feed apparatus including a power feed resonance device to supply
alternate-current power to an electronic apparatus by resonance in
a noncontact manner, and an alternate-current power source section
to generate the alternate-current power having a frequency
corresponding to a resonant frequency of the power feed resonance
device and supply the alternate-current power to the power feed
resonance device; a noncontact relay apparatus including a relay
resonance device to receive supply of the alternate-current power
from the power feed resonance device of the noncontact power feed
apparatus by resonance in a noncontact manner and relay the
alternate-current power to another electronic apparatus by
resonance in a noncontact manner, a relay-side rectifier circuit to
form direct-current power based on the alternate-current power
supplied from the relay resonance device and output the
direct-current power, and a movement means for moving the
noncontact relay apparatus by being driven by the direct-current
power from the relay-side rectifier circuit; and at least one
noncontact power reception apparatus including a power reception
resonance device to receive supply of the alternate-current power
from the relay resonance device of the noncontact relay apparatus
by magnetic field resonance in a noncontact manner, a
power-reception-side rectifier circuit to form direct-current power
based on the alternate-current power supplied from the power
reception resonance device and output the direct-current power, and
a load means driven by the direct-current power from the
power-reception-side rectifier circuit.
2. The noncontact power feed system according to claim 1, wherein
the noncontact power feed apparatus includes a power-feed-side
coupling device that is provided between the alternate-current
power source section and the power feed resonance device, and
receives the supply of the alternate-current power from the
alternate-current power source section and supplies the
alternate-current power to the power feed resonance device by
electromagnetic induction, wherein the noncontact relay apparatus
includes a relay-side coupling device that is provided between the
relay resonance device and the relay-side rectifier circuit, and
receives the supply of the alternate-current power from the relay
resonance device by the electromagnetic induction and supplies the
alternate-current power to the relay-side rectifier circuit, and
wherein the at least one noncontact power reception apparatus
includes a power-reception-side coupling device that is provided
between the power reception resonance device and the
power-reception-side rectifier circuit, and receives the supply of
the alternate-current power from the power reception resonance
device by the electromagnetic induction and supplies the
alternate-current power to the power-reception-side rectifier
circuit.
3. The noncontact power feed system according to claim 1, wherein
the noncontact power feed apparatus includes a transmission means
for transmitting information, wherein the noncontact relay
apparatus includes a reception/transmission means for receiving the
information from the noncontact power feed apparatus and
transmitting the information to the at least one noncontact power
reception apparatus, wherein the load means of the at least one
noncontact power reception apparatus is a display means, and
wherein the at least one noncontact power reception apparatus
includes a reception means for receiving information, and a display
control means for displaying the information received by the
reception means on the display means.
4. The noncontact power feed system according to claim 1, wherein
the noncontact relay apparatus includes an acceptance means for
accepting an input of information, and a transmission means for
transmitting the information accepted via the acceptance means,
wherein the load means of the at least one noncontact power
reception apparatus is a display means, and wherein the at least
one noncontact power reception apparatus includes a reception means
for receiving information, and a display control means for
displaying the information received by the reception means on the
display means.
5. A noncontact relay apparatus, comprising: a relay resonance
device to receive supply of alternate-current power from a power
feed resonance device of a noncontact power feed apparatus by
resonance in a noncontact manner and relay the alternate-current
power to another electronic apparatus by resonance in a noncontact
manner; a relay-side rectifier circuit to form direct-current power
based on the alternate-current power supplied from the relay
resonance device and output the direct-current power; and a moving
means for moving the noncontact relay apparatus by being driven by
the direct-current power from the relay-side rectifier circuit.
6. The noncontact relay apparatus according to claim 5, further
comprising a relay-side coupling device that is provided between
the relay resonance device and the relay-side rectifier circuit,
and receives the supply of the alternate-current power from the
relay resonance device by electromagnetic induction and supplies
the alternate-current power to the relay-side rectifier
circuit.
7. The noncontact relay apparatus according to claim 5, further
comprising a reception/transmission means for receiving information
from the noncontact power feed apparatus and transmitting the
information to a noncontact power reception apparatus.
8. The noncontact relay apparatus according to claim 5, further
comprising: an acceptance means for accepting an input of
information; and a transmission means for transmitting the
information accepted via the acceptance means.
9. A noncontact power reception apparatus, comprising: a power
reception resonance device to receive supply of alternate-current
power from a relay resonance device of a noncontact power
reception/relay apparatus having a movable structure by magnetic
field resonance in a noncontact manner; a power-reception-side
rectifier circuit to form direct-current power based on the
alternate-current power supplied from the power reception resonance
device and output the direct-current power; and a load means driven
by the direct-current power from the power-reception-side rectifier
circuit.
10. The noncontact power reception apparatus according to claim 9,
further comprising a power-reception-side coupling device that is
provided between the power reception resonance device and the
power-reception-side rectifier circuit, and receives supply of the
alternate-current power from the power reception resonance device
by electromagnetic induction and supplies the alternate-current
power to the power-reception-side rectifier circuit.
11. The noncontact power reception apparatus according to claim 9,
wherein the load means is a display means, the noncontact power
reception apparatus further comprising: a reception means for
receiving information; and a display control means for displaying
the information received by the reception means on the display
means.
12. A noncontact power feed method in a noncontact power feed
system, comprising: transmitting, by a first apparatus,
alternate-current power via a transmission resonance coil in a
resonance system; receiving, by a second apparatus, the
alternate-current power transmitted from the first apparatus via a
reception/transmission resonance coil resonating at a frequency
that is one of the same and substantially the same as a frequency
of the transmission resonance coil of the first apparatus; relaying
and transmitting, by the second apparatus, the alternate-current
power received from the first apparatus via the
reception/transmission resonance coil; moving, by the second
apparatus, the second apparatus by using the alternate-current
power received from the first apparatus; receiving, by a third
apparatus, the alternate-current power transmitted from the second
apparatus via a reception resonance coil resonating at a frequency
that is one of the same and substantially the same as the frequency
of the reception/transmission resonance coil of the second
apparatus when the second apparatus comes close to the third
apparatus; and driving, by the third apparatus, a predetermined
load circuit by using the alternate-current power received from the
second apparatus.
13. A noncontact power feed method in a noncontact relay apparatus,
comprising: receiving alternate-current power transmitted from a
noncontact power feed apparatus via a reception/transmission
resonance coil resonating at a frequency that is one of the same
and substantially the same as a frequency of a transmission
resonance coil of the noncontact power feed apparatus; relaying and
transmitting the alternate-current power received from the
noncontact power feed apparatus via the reception/transmission
resonance coil; and moving the noncontact relay apparatus by using
the alternate-current power received from the noncontact power feed
apparatus.
14. A noncontact power feed method in a noncontact power reception
apparatus, comprising: receiving alternate-current power
transmitted from a noncontact power reception/relay apparatus via a
reception resonance coil resonating at a frequency that is one of
the same and substantially the same as a frequency of a
reception/transmission resonance coil of the noncontact power
reception/relay apparatus when the noncontact power reception/relay
apparatus having a movable structure comes close to the noncontact
power reception apparatus; and driving a predetermined load circuit
by using the alternate-current power received from the noncontact
power reception/relay apparatus.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a noncontact power feed
system that feeds power by using resonance phenomena such as
magnetic field resonance and electric field rescnance, an apparatus
used in the system, and a noncontact power feed method used for the
system and the apparatus.
[0003] 2. Description of the Related Art
[0004] As techniques of enabling electric energy to be transmitted
in a noncontact manner, there are an electromagnetic induction
system and a magnetic field resonance system. The electromagnetic
induction system and the magnetic field resonance system are
different from each other in various points as described below, and
in recent years, an energy transmission using the magnetic field
resonance system has attracted attention.
[0005] FIG. 11 is a block diagram showing a structural example of a
magnetic-field-resonance-type noncontact power feed system in which
a power feed source and a power feed destination have a one-to-one
relationship. The magnetic-field-resonance-type noncontact power
feed system shown in FIG. 11 includes a power feed source 100 and a
power feed destination 200.
[0006] As shown in FIG. 11, the power feed source 100 such as a
charging base includes an AC power source 101, an excitation device
(coupling device) 102, and a resonance device 103. Further, the
power feed destination 200 such as a cellular phone terminal
includes a resonance device 201, an excitation device (coupling
device) 202, and a rectifier circuit 203.
[0007] The excitation device 102 and the resonance device 103 of
the power feed source 100, and the resonance device 201 and the
excitation device 202 of the power feed destination 200 are each
constituted of an air-cored coil. Inside the power feed source 100,
the excitation device 102 and the resonance device 103 are strongly
coupled to each other by electromagnetic induction. Similarly,
inside the power feed destination 200, the resonance device 201 and
the excitation device 202 are strongly coupled to each other by
electromagnetic induction.
[0008] When a self-resonant frequency of the resonance device
(air-cored coil) 103 of the power feed source 100 coincides with
that of the resonance device (air-cored coil) 201 of the power feed
destination 200, a magnetic field resonance relationship is
obtained, in which a coupling amount becomes a maximum and a loss
becomes a minimum.
[0009] Specifically, in the noncontact power feed system shown in
FIG. 11, AC power (energy such as alternating current) having a
predetermined frequency from the AC power source 101 is first
supplied to the excitation device 102, which induces AC power in
the resonance device 103 by electromagnetic induction in the power
feed source 100. In this case, a frequency of the AC power that is
generated in the AC power source 101 is set to be the same as the
self-resonant frequencies of the resonance device 103 of the power
feed source 100 and the resonance device 201 of the power feed
destination 200.
[0010] As described above, the resonance device 103 of the power
feed source 100 and the resonance device 201 of the power feed
destination 200 are provided in the magnetic field resonance
relationship. Therefore, the AC power (energy such as alternating
current) is supplied from the resonance device 103 to the resonance
device 201 in a noncontact manner at the self-resonant
frequency.
[0011] In the power feed destination 200, the AC power supplied
from the resonance device 103 of the power feed source 100 is
received by the resonance device 201. The AC power from the
resonance device 201 is supplied to the rectifier circuit 203 via
the excitation device 202 by electromagnetic induction, and
converted into DC power and output from the rectifier circuit
203.
[0012] Thus, the AC power is supplied from the power feed source
100 to the power feed destination 200 in a noncontact manner. It
should be noted that the DC power output from the rectifier circuit
203 is supplied to a charging circuit connected with a battery, and
used for charging the battery.
[0013] In the noncontact power feed system in which the power feed
source 100 and the power feed destination 200 that are structured
as shown in FIG. 11 have a one-to-one correspondence, the following
features are found.
[0014] The noncontact power feed system has a relationship as shown
in FIG. 12A, between a frequency of an AC power source and a
coupling amount. As is found from FIG. 12A, the coupling amount is
not increased even when the frequency of the AC power source is low
or high, but the coupling amount becomes a maximum only at a
specific frequency at which a magnetic field resonance phenomenon
is caused. In other words, frequency selectivity is shown by
magnetic field resonance.
[0015] Moreover, the noncontact power feed system has a
relationship as shown in FIG. 12B, between a distance from the
resonance device 103 to the resonance device 201, and a coupling
amount. As is found from FIG. 12B, the coupling amount is smaller
as the distance between the resonance devices is larger.
[0016] However, a shorter distance between the resonance devices
does not increase the coupling mount, and a distance at which the
coupling mount becomes a maximum exists at a certain frequency.
Further, it is found from FIG. 12B that if the distance between the
resonance devices has a certain range, a coupling mount above a
certain level can be ensured.
[0017] In addition, the noncontact power feed system has a
relationship as shown in FIG. 12C, between a resonant frequency and
a distance between the resonance devices at which a maximum
coupling mount is obtained. Specifically, it is found that when the
resonant frequency is low, the distance between the resonance
devices is large. Further, it is found that when the resonant
frequency is high, a maximum coupling mount is obtained by
narrowing the interval between the resonance devices.
[0018] In an electromagnetic-induction-type noncontact power feed
system that has been widely used in recent years, it is necessary
to share a magnetic flux between a power feed source and a power
feed destination and to arrange the power feed source and the power
feed destination very close to each other in order to efficiently
transmit power, in which alignment of coupling axes is also
important.
[0019] On the other hand, in the noncontact power feed system using
the magnetic field resonance phenomenon, it is possible to transmit
power with the resonance devices being more away from each other
than in the electromagnetic induction system by the principle of
the magnetic field resonance phenomenon, as described above. In
addition, this noncontact power feed system has an advantage that
transmission efficiency is not decreased so much even if the
alignment of axes is not favorable.
[0020] In summary, as shown in FIG. 13, there are differences
between the magnetic-field-resonance-type noncontact power feed
system and the electromagnetic-induction-type noncontact power feed
system. As shown in FIG. 13, the magnetic-field-resonance-type
noncontact power feed system has an advantage in a deviation
between transmission/reception coils (resonance devices), with the
result that a transmission distance can be made longer.
[0021] Accordingly, in the case of the
magnetic-field-resonance-type noncontact power feed system, it is
possible to charge a plurality of power feed destinations (cellular
phone terminals) by placing them on one power feed source (charging
base) as shown in FIG. 14.
[0022] It should be noted that US Patent Application No.
2007/0222542 discloses a technique regarding a power transmission
system using the magnetic field resonance system as described
above.
SUMMARY OF THE INVENTION
[0023] Incidentally, in a case of a magnetic-field-resonance-type
power supply technique, for example, a transmission distance is
longer and a deviation between transmission/reception coils causes
less influence than in an electromagnetic-induction-type power
supply technique that has been used from the past, as described
above. In addition, the magnetic-field-resonance-type power supply
technique allows a repeater to intervene and accordingly has high
flexibility.
[0024] Therefore, in the case of the magnetic-field-resonance-type
power supply technique, it is highly possible to enable new
power-supply mode and a new power-use mode in the new power-supply
mode to be created, not merely to supply power from a power feed
source to a power feed destination. This applies to not only the
magnetic-field-resonance-type noncontact power feed system but also
a noncontact power feed system of another resonance type other than
an electromagnetic resonance type, for example.
[0025] In view of the points described above, it is desirable to
provide a new power-supply mode that uses a resonance-type power
supply technique, and a new power-use mode in the new power-supply
mode.
[0026] According to an embodiment of the present invention, there
is provided a noncontact power feed system including: a noncontact
power feed apparatus including a power feed resonance device to
supply alternate-current power to an electronic apparatus by
resonance in a noncontact manner, and an alternate-current power
source section to generate the alternate-current power having a
frequency corresponding to a resonant frequency of the power feed
resonance device and supply the alternate-current power to the
power feed resonance device; a noncontact relay apparatus including
a relay resonance device to receive supply of the alternate-current
power from the power feed resonance device of the noncontact power
feed apparatus by resonance in a noncontact manner and relay the
alternate-current power to another electronic apparatus by
resonance in a noncontact manner, a relay-side rectifier circuit to
form direct-current power based on the alternate-current power
supplied from the relay resonance device and output the
direct-current power, and a movement means for moving the
noncontact relay apparatus by being driven by the direct-current
power from the relay-side rectifier circuit; and at least one
noncontact power reception apparatus including a power reception
resonance device to receive supply of the alternate-current power
from the relay resonance device of the noncontact relay apparatus
by magnetic field resonance in a noncontact manner, a
power-reception-side rectifier circuit to form direct-current power
based on the alternate-current power supplied from the power
reception resonance device and output the direct-current power, and
a load means driven by the direct-current power from the
power-reception-side rectifier circuit.
[0027] By the noncontact power feed system according to the
embodiment of the present invention, in the noncontact power feed
apparatus, the alternate-current power from the alternate-current
power source is transmitted via the power feed resonance device in
the noncontact manner.
[0028] In the noncontact relay apparatus, the alternate-current
power from the noncontact power feed apparatus is received via the
relay resonance device and supplied to the movement means via the
relay-side rectifier circuit, with the result that the noncontact
relay apparatus is moved. Simultaneously, the alternate-current
power received via the relay resonance device is transmitted to
another electronic apparatus (noncontact power reception apparatus)
via the relay resonance device.
[0029] Specifically, the noncontact relay apparatus has a function
of relaying the alternate-current power from the noncontact power
feed apparatus to another electronic apparatus (noncontact power
reception apparatus) while moving by the alternate-current power
from the noncontact power feed apparatus.
[0030] Further, in the at least one noncontact power reception
apparatus, the alternate-current power from the movable noncontact
relay apparatus is received via the power reception resonance
device and supplied to a load circuit via the power-reception-side
rectifier circuit, with the result that the load circuit is
driven.
[0031] With this structure, the alternate-current power (energy
such as alternating current) from the noncontact power feed
apparatus can be supplied to the noncontact relay apparatus in the
noncontact manner and can move the noncontact relay apparatus.
Then, the alternate-current power (energy such as alternating
current) can be relayed and supplied to the at least one noncontact
power reception apparatus via the movable noncontact relay
apparatus.
[0032] As described above, it is possible to supply the
alternate-current power to the at least one noncontact power
reception apparatus as a target via the movable noncontact relay
apparatus, and operate the load means in the at least one
noncontact power reception apparatus.
[0033] Accordingly, it is possible to drive the load means in the
at least one noncontact power reception apparatus by supplying
power to the at least one noncontact power reception apparatus not
only in the noncontact manner but also using the moving noncontact
relay apparatus as a relay.
[0034] Specifically, through the mediation of a moving noncontact
power reception/relay apparatus, it is possible to provide a new
power-supply mode that uses a power supply technique of a so-called
resonance type such as a magnetic field resonance type and a new
power-use mode in the new power-supply mode.
[0035] According to the embodiment of the present invention, it is
possible to realize a new power-supply mode that uses a
resonance-type power supply technique and a new power-use mode in
the new power-supply mode.
[0036] These and other objects, features and advantages of the
present invention will become more apparent in light of the
following detailed description of best mode embodiments thereof, as
illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0037] FIG. 1 is a diagram for explaining a structural example of a
magnetic-field-resonance-type noncontact power feed system
according to a first embodiment of the present invention;
[0038] FIG. 2 is a diagram for explaining an outer appearance of
the noncontact power feed system according to the first
embodiment;
[0039] FIG. 3 is a diagram for explaining a structural example of a
moving body of the noncontact power feed system according to the
first embodiment;
[0040] FIG. 4 is a diagram for explaining a structural example of a
power feed destination (decorative illumination body) of the first
embodiment;
[0041] FIG. 5 is a diagram for explaining a noncontact power feed
system according to a second embodiment;
[0042] FIG. 6 is a diagram for explaining a use mode of the
noncontact power feed system according to the second
embodiment;
[0043] FIG. 7 is a diagram for explaining a structural example of a
power feed source of the second embodiment;
[0044] FIG. 8 is a diagram for explaining a structural example of a
moving body of the second embodiment;
[0045] FIG. 9 is a diagram for explaining a structural example of a
power feed destination of the second embodiment;
[0046] FIG. 10 is a diagram showing an expression used for
calculating a resonant frequency of a resonance device;
[0047] FIG. 11 is a diagram for explaining a
magnetic-field-resonance-type noncontact power feed system in
related art;
[0048] FIG. 12 are diagrams for explaining features of the
magnetic-field-resonance-type noncontact power feed system;
[0049] FIG. 13 is a table showing comparison results of the
magnetic-field-resonance-type noncontact power feed system and an
electromagnetic-induction-type noncontact power feed system;
and
[0050] FIG. 14 is a diagram for explaining a specific example of
the magnetic-field-resonance-type noncontact power feed system.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0051] Hereinafter, embodiments of an apparatus and a method
according to the present invention will be described with reference
to the drawings. Though the present invention is applicable to
various resonance systems such as a magnetic field resonance
system, an electric field resonance system, and an electromagnetic
resonance system, an example in which the magnetic field resonance
system is used will be described below.
First Embodiment
Outline of Noncontact Power Feed System of First Embodiment
[0052] FIG. 1 is a diagram for explaining a structural example of a
magnetic-field-resonance-type noncontact power feed system
according to a first embodiment of the present invention. As shown
in FIG. 1, the noncontact power feed system of this embodiment
includes a power feed source 1, a moving body 2, and a power feed
destination 3. It should be noted that a plurality of power feed
destinations that are similarly structured can be used, which will
be described later in detail.
[0053] The power feed source 1 uses a magnetic field resonance
system to supply power to another electronic apparatus in a
noncontact manner, thus realizing a function as a noncontact power
feed apparatus.
[0054] The moving body 2 receives power from the power feed source
1 and has a function as a relay apparatus that supplies the power
to another electronic apparatus and a function of using the power
to drive a drive motor thereof, thus realizing a function as a
noncontact relay apparatus.
[0055] The power feed destination 3 receives supply of power from
the power feed source 1 via the moving body 2 and uses the power to
drive a load circuit thereof, thus realizing a function as a
noncontact power reception apparatus in this embodiment.
[0056] As shown in FIG. 1, the power feed source 1 includes an AC
power source 11, a coupling coil (coupling device (excitation
device)) 12, and a transmission resonance coil (resonance device)
13.
[0057] As shown in FIG. 1, the moving body 2 includes a relay
resonance coil (resonance device) 21 that receives power (AC power)
from the power feed source 1 and transmits the power to the power
feed destination 3. It should be noted that though not shown in
FIG. 1, the moving body 2 includes a coupling coil (coupling device
(excitation device)), a rectifier circuit, a drive motor, and the
like and also has a structure in which part of the power supplied
from the power feed source 1 is used for driving a drive motor
thereof.
[0058] As shown in FIG. 1, the power feed destination 3 includes a
reception resonance coil (resonance device) 31, a coupling coil
(coupling device (excitation device)) 32, a rectifier circuit 33,
and a load circuit 34. It should be noted that the load circuit 34
of the power feed destination 3 is constituted of an LED (Light
Emitting Diode), an LED driver, and the like.
[0059] The coupling coil 12 and the transmission resonance coil 13
of the power feed source 1, the relay resonance coil 21 and the
not-shown coupling coil of the moving body 2, and the reception
resonance coil 31 and the coupling coil 32 of the power feed
destination 3 each have a structure of an air-cored coil.
[0060] The AC power source 11 of the power feed source 1 generates
AC power (energy such as alternating current) having a frequency
that is the same or substantially the same as a self-resonant
frequency of the transmission resonance coil 13 of the power feed
source 1, and supplies it to the excitation device 12.
[0061] It should be noted that each of the relay resonance coil 21
of the moving body 2 and the reception resonance coil 31 of the
power feed destination 3 also has a self-resonant frequency that is
the same or substantially the same as that of the transmission
resonance coil 13 of the power feed source 1.
[0062] In other words, in the magnetic-field-resonance-type
noncontact power feed system shown in FIG. 1, the transmission
resonance coil 13 of the power feed source 1, the relay resonance
coil 21 of the moving body 2, and the reception resonance coil 31
of the power feed destination 3 each have the same or substantially
the same resonant frequency.
[0063] Further, in order to generate AC power having a target
frequency, the AC power source 11 of the power feed source 1
includes a Colpitts oscillator or a Hartley oscillator, for
example.
[0064] The coupling coil 12 is a device that supplies AC power to
the transmission resonance coil 13 by being oscillated by the AC
power from the AC power source 11. The coupling coil 12 that
receives supply of the AC power from the AC power source 11 and the
transmission resonance coil 13 are strongly coupled to each other
by electromagnetic induction. Accordingly, the AC power from the AC
power source 11 is supplied to the transmission resonance coil 13
via the coupling coil 12.
[0065] It should be noted that the coupling coil 12 also plays a
role in preventing reflection of an electric signal by matching
impedance of the AC power source 11 to that of the transmission
resonance coil 13. That is, in the magnetic-field-resonance-type
noncontact power feed system, an unmodulated sine wave having a
center frequency of f0 is normally used. Since the unmodulated sine
wave is unmodulated, an occupied frequency band is narrow (0 Hz is
ideal).
[0066] Accordingly, a frequency band necessary for a resonance coil
that transmits the unmodulated sine wave may also be narrow, e.g.,
several Hz, but in order to improve transmission efficiency, a low
loss (high "Q" factor) is needed. It should be noted that here, the
value "Q" represents a sharpness of a resonant peak of a resonator
circuit. If a resonant peak becomes sharp, the transmission
efficiency of power (AC power) can be improved.
[0067] In other words, in order to obtain high transmission
efficiency in a magnetic-field-resonance-type noncontact power
transmission, it is desirable to obtain as high Q factor as
possible in the transmission resonance coil 13 of the power feed
source 1 or the reception resonance coil 31 of the power feed
destination 3.
[0068] However, when the transmission resonance coil 13 is directly
connected to the AC power source 11 in the power feed source 1 or
the reception resonance coil 31 is directly connected to the
rectifier circuit 33 in the power feed destination 3, a Q factor of
the transmission resonance coil 13 or reception resonance coil 31
is lowered due to the influence of circuit impedance.
[0069] To avoid the above situation, direct connection of the
transmission resonance coil 13 to the AC power source 11 is avoided
in the power feed source 1 by using the coupling coil 12, with the
result that impedance of the transmission resonance coil 13 is kept
high and a Q factor thereof is also kept high.
[0070] Moreover, the transmission resonance coil 13 is a coil that
generates a magnetic field by the AC power supplied from the
coupling coil 12. The transmission resonance coil 13 has inductance
and capacitance. The transmission resonance coil 13 has a maximum
strength of the magnetic field at a resonant frequency.
[0071] FIG. 10 is a diagram showing an expression used for
calculating a resonant frequency fr of the transmission resonance
coil 13. In Expression (1) shown in FIG. 10, a letter L represents
inductance of the transmission resonance coil 13 and a letter C
represents capacitance thereof.
[0072] Accordingly, a resonant frequency of the transmission
resonance coil 13 is determined by inductance L and capacitance C
of the transmission resonance coil 13. As described above, since
the transmission resonance coil 13 is constituted of an air-cored
coil, line-to-line capacitance of the transmission resonance coil
13 serves as capacitance. Then, the transmission resonance coil 13
generates a magnetic field in an axial direction of the coil.
[0073] The relay resonance coil 21 of the moving body 2 is a device
for receiving supply of the AC power from the power feed source 1
by magnetic field coupling due to magnetic field resonance. The
relay resonance coil 21 of the moving body 2 has inductance L and
capacitance C as in the case of those of the transmission resonance
coil 13 of the power feed source 1 that are described using
Expression (1) of FIG. 10, and has a resonant frequency that is the
same or substantially the same as that of the transmission
resonance coil 13 of the power feed source 1.
[0074] As described above, since the relay resonance coil 21 of the
moving body 2 has a structure of an air-cored coil, line-to-line
capacitance thereof serves as capacitance. Then, the relay
resonance coil 21 of the moving body 2 is connected to the
transmission resonance coil 13 of the power feed source 1 by
magnetic field resonance, as shown in FIG. 1.
[0075] Accordingly, the AC power (energy such as alternating
current) at a resonant frequency is supplied from the transmission
resonance coil 13 of the power feed source 1 to the relay resonance
coil 21 of the moving body 2 in a noncontact manner by magnetic
field resonance.
[0076] The relay resonance coil 21 of the moving body 2 is also
connected to the reception resonance coil 31 of the power feed
destination 3 by the magnetic field coupling due to the magnetic
field resonance.
[0077] Specifically, the reception resonance coil 31 of the power
feed destination 3 is a device for receiving supply of the AC power
from the power feed source 1, the AC power being relayed via the
moving body 2, by the magnetic field coupling due to the magnetic
field resonance. The reception resonance coil 31 of the power feed
destination 3 has inductance L and capacitance C as in the case of
those of the transmission resonance coil 13 of the power feed
source 1 that are described using Expression (1) of FIG. 10, and
has a resonant frequency that is the same or substantially the same
as that of the transmission resonance coil 13 of the power feed
source 1.
[0078] As described above, since the reception resonance coil 31 of
the power feed destination 3 has a structure of an air-cored coil,
line-to-line capacitance thereof serves as capacitance. Then, as
shown in FIG. 1, the reception resonance coil 31 of the power feed
destination 3 is connected to the relay resonance coil 21 of the
moving body 2 by the magnetic field resonance.
[0079] Accordingly, the AC power (energy such as alternating
current) at a resonant frequency is supplied from the relay
resonance coil 21 of the moving body 2 to the reception resonance
coil 31 of the power feed destination 3 in a noncontact manner by
the magnetic field resonance.
[0080] Then, as described above, the reception resonance coil 31
and the coupling coil 32 are coupled to each other by
electromagnetic induction in the power feed destination 3, and the
AC power is supplied from the reception resonance coil 31 to the
rectifier circuit 33 via the coupling coil 32.
[0081] It should be noted that the coupling coil 32 of the power
feed destination 3 also plays a role in preventing reflection of an
electric signal by matching impedance of the reception resonance
coil 31 to that of the rectifier circuit 33, as in the case of the
coupling coil 12 of the power feed source 1.
[0082] Specifically, as in the case of the coupling coil 12 of the
power feed source 1, direct connection of the reception resonance
coil 31 to the rectifier circuit 33 is avoided in the power feed
destination 3 by using the coupling coil 32, with the result that
impedance of the reception resonance coil 31 is kept high and a Q
factor thereof is also kept high.
[0083] The rectifier circuit 33 forms DC power to be supplied to
the load circuit 34 as a subsequent stage, based on the AC power
supplied via the coupling coil 32, and then supplies the DC power
to the load circuit 34. The load circuit 34 is constituted of an
LED, an LED driver, and the like as described above and also to be
described later in detail, and receives supply of the AC power to
cause the LED to emit light.
[0084] It should be noted that though described later in detail,
the moving body 2 also includes a coupling coil, a rectifier
circuit, a drive motor as a load circuit, and the like.
Accordingly, the moving body 2 uses the power supplied from the
power feed source 1 to drive a drive motor thereof, as well as
relaying the power to the power feed destination 3.
Outer Appearance of Noncontact Power Feed System of First
Embodiment
[0085] FIG. 2 is a diagram for explaining an outer appearance of
the noncontact power feed system according to the first embodiment.
In a case of the first embodiment, for example, the moving body
(circulating car) 2, a circular guide plate 5 that is formed to
guide travel of the moving body 2, and the power feed destinations
(decorative illumination bodies) 3(1) to 3(8) are provided on a
placement base 4 having about several tens of centimeters on each
side. On a lower side of the placement base 4, the power feed
source 1 that supplies power to the moving body 2 is provided.
[0086] A size of the transmission resonance coil 13 of the power
feed source 1 and a positional relationship between the
transmission resonance coil 13 and the moving body 2, or between
the transmission resonance coil 13 and each power feed destination
3 are set (determined) such that the power feed source 1 can supply
power to only the moving body 2.
[0087] Further, the moving body 2 receives supply of power from the
power feed source 1 and uses the power to drive a drive motor
thereof, thus moving the moving body 2. Then, the moving body 2
relays the power supplied from the power feed source 1 to, out of
the power feed destinations 3(1) to 3(8), a power feed destination
3 that is located close to the moving body 2 after the moving body
2 is moved.
[0088] In this case, the moving body 2 may be incapable of relaying
the power to all the power feed destinations 3(1) to 3(8) at the
same time, but is capable of relaying the power supplied from the
power feed source 1 to only one or two adjacent power feed
destinations 3 that are to be more strongly coupled to the moving
body 2 as the magnetic field resonance becomes stronger.
[0089] Accordingly, the moving body 2 drives the drive motor by the
power supplied from the power feed source 1 in a noncontact manner,
and circularly moves on the placement base 4 along the circular
guide plate 5. Simultaneously, the moving body 2 relays the power
supplied from the power feed source 1 in a noncontact manner and
supplies the power to, out of the power feed destinations 3(1) to
3(8), only a power feed destination 3 located close thereto, and
causes an LED of the power feed destination 3 to emit light.
[0090] Specifically, a large amount of power is supplied to only a
power feed destination 3 (decorative illumination body) to which
the moving body 2 comes close. As a result, the LEDs of the power
feed destinations 3(1) to 3(8) arranged along the circular guide
plate 5 sequentially emit light with the circular movement of the
moving body 2 along the circular guide plate 5.
Structural Example of Moving Body (Circulating Car) 2
[0091] Next, a structural example of the moving body (circulating
car) 2 of the noncontact power feed system according to the first
embodiment will be described. FIG. 3 is a diagram for explaining a
structural example of the moving body 2 of the noncontact power
feed system according to the first embodiment.
[0092] As shown in FIG. 3, the moving body 2 is in an automobile
shape. The moving body 2 includes the relay resonance coil 21, a
coupling coil 22, a rectifier circuit 23, and a drive motor section
24 and has a structure in which a rotation of a drive motor of the
drive motor section 24 is transmitted to drive wheels of the moving
body 2.
[0093] Then, though described above, the relay resonance coil 21
receives supply of the AC power (energy such as alternating
current) from the transmission resonance coil 13 of the power feed
source 1, to which the relay resonance coil 21 is coupled by
magnetic field resonance, and supplies part of the AC power to the
rectifier circuit 23 via the coupling coil 22.
[0094] The rectifier circuit 23 forms DC power from the AC power
supplied thereto, and supplies the DC power to the drive motor
section 24. The drive motor section 24 drives the drive motor to
rotate by the DC power supplied thereto and transmits the rotation
to the drive wheels.
[0095] Accordingly, the drive wheels of the moving body 2 rotate
and the moving body 2 circularly moves (circularly travels) along
the circular guide plate 5 on the placement base 4 as described
with reference to FIG. 2.
[0096] Further, the relay resonance coil 21 of the moving body 2 is
also coupled to the reception resonance coil 31 of the power feed
destination 3 by magnetic field resonance, and sequentially relays
(supplies) part of the power from the power feed source 1 to each
of the power feed destinations 3(1) to 3(8) to which the moving
body 2 comes close.
[0097] In this manner, the moving body 2 functions as a moving
relay (moving repeater) that relays power from the power feed
source 1 to an adjacent power feed destination 3, as well as using
the power to move the moving body 2.
Structural Example of Power Feed Destination (Decorative
Illumination Body) 3
[0098] Next, a structural example of the power feed destination
(decorative illumination body) 3 of the noncontact power feed
system according to the first embodiment will be described. It
should be noted that as described with reference to FIG. 2, the
plurality of power feed destinations 3(1) to 3(8) each having the
same structure are used. Accordingly, each structure of the
plurality of power feed destinations 3(1) to 3(8) will be described
as a structure of the power feed destination 3 hereinafter.
[0099] FIG. 4 is a diagram for explaining the structural example of
the power feed destination (decorative illumination body) 3 of the
first embodiment. As shown in FIG. 4, the power feed destination 3
is constituted of a circuit accommodation portion 30A and a
decorative illumination arrangement portion (tree portion) 30B.
[0100] As shown in FIG. 4, the circuit accommodation portion 30A
includes the reception resonance coil 31, the coupling coil 32, the
rectifier circuit 33, and an LED driver circuit 341 as a part of
the load circuit 34.
[0101] Further, the decorative illumination arrangement portion 30B
includes a plurality of LEDs 342(1), 342(2), 342(3), . . . , as a
part of the load circuit 34.
[0102] As described above, the reception resonance coil 31 receives
supply of power (AC power) from the power feed source 1 via the
relay resonance coil 21 of the moving body 2 that is coupled
thereto by magnetic field resonance, and supplies the power to the
rectifier circuit 33 via the coupling coil 32.
[0103] The rectifier circuit 33 forms DC power from the AC power
supplied thereto and supplies the DC power to the LED driver
circuit 341. The LED driver circuit 341 forms a drive current for
the LEDs 342(1), 342(2), 342(3), . . . , from the DC power supplied
thereto, and supplies the drive current to each of the LEDs 342(1),
342(2), 342(3), . . . .
[0104] Accordingly, the power feed destination (decorative
illumination body) 3 can cause the LEDs 342(1), 342(2), 342(3), . .
. , which are arranged in the decorative illumination arrangement
portion 30B, to emit light when receiving the power supplied from
the power feed source 1 via the moving body 2.
[0105] As described above, though the noncontact power feed system
according to the first embodiment is constituted of the power feed
source 1, the moving body 2, and the power feed destination 3, they
are not connected to one another with wires and the power feed
source 1 can supply power to the moving body 2 and each of the
plurality of power feed destinations 3.
Effects of First Embodiment
[0106] As described above, it is unnecessary to connect the power
feed source 1, the moving body 2, and the plurality of power feed
destinations 3(1) to 3(8) to one another with wires in the
noncontact power feed system of the first embodiment, with the
result that the apparatuses constituting the system can be flexibly
arranged.
[0107] For example, when the placement base 4 shown in FIG. 2 is
constituted of a transparent acrylic plate or the like, it is
possible to arrange the moving body 2 and each of the power feed
destinations 3(1) to 3(8) in a floating state in which the moving
body 2 and the power feed destinations 3(1) to 3(8) are away from
the power feed source 1.
[0108] Further, in a case where the decorative illumination bodies
are used as the power feed destinations as described above, it is
possible to cause the decorative illumination bodies to emit light
with an extremely simple structure. In other words, complicated
microcomputer control or the like is completely unnecessary and it
is possible to control the decorative illumination bodies to emit
light sequentially.
[0109] Further, though the decorative illumination bodies are used
as the power feed destinations 3 in the noncontact power feed
system of the first embodiment described above, if members that
mechanically operate by power are arranged instead of the
decorative illumination bodies, it is possible to cause the members
to mechanically operate in a wireless manner in sequence.
[0110] Members having various structures can be used as the load
circuit 34, for example, in which the motor is driven and rotated
to lift an object each time the moving body 2 comes close, or a
shutter is released to take a picture each time the moving body 2
comes close.
[0111] Further, in the case of the noncontact power feed system of
the first embodiment described above, the power feed destination 3
is constituted of the decorative illumination body and has one
purpose to attract attention of people, with the result that the
effect thereof can be increased with the moving body 2 being
circularly moved.
[0112] Further, the power can be transmitted/received among the
apparatuses in a noncontact manner, with the result that it is
possible to enjoy advantages that wiring as in the related art is
not carried out, the apparatuses can be arranged easily, a failure
due to wrong wiring or the like is not caused, and the like.
[0113] As described above, in the case of the noncontact power feed
system of the first embodiment, by using the moving body 2 as a
relay apparatus of power, it is possible to form a noncontact power
feed system that is pleasant to the eye without carrying out
complicated wiring or the like.
[0114] Moreover, the noncontact power feed system of the first
embodiment can be used as, for example, a display in various shops
in addition to a toy for kids.
Second Embodiment
Outline of Noncontact Power Feed System of Second Embodiment
[0115] The noncontact power feed system according to the first
embodiment described above has a relatively small size such that
the noncontact power feed system can be provided on a table, for
example. On the other hand, a noncontact power feed system
according to a second embodiment is formed as one of amusement
attractions in a theme park, in which a moving body can be moved
while taking humans thereon.
[0116] FIG. 5 is a diagram for explaining the noncontact power feed
system according to the second embodiment. As shown in FIG. 5, the
noncontact power feed system according to the second embodiment
includes a plurality of power feed sources 1(1), 1(2), 1(3), . . .
, a moving body 2A having a structure of an automobile, and a
plurality of power feed destinations 3(1), 3(2), 3(3), . . . .
[0117] Each of the plurality of power feed sources 1(1), 1(2),
1(3), . . . realizes a function as a noncontact power feed
apparatus. Further, the moving body 2A realizes a function as a
noncontact relay apparatus. Furthermore, each of the plurality of
power feed destinations 3(1), 3(2), 3(3), . . . realizes a function
as a noncontact power reception apparatus.
[0118] The plurality of power feed sources 1(1), 1(2), 1(3), . . .
are arranged with intervals therebetween on a traveling road on
which the moving body 2A travels so that the moving body 2A can be
supplied with power. Each of the plurality of power feed sources
1(1), 1(2), 1(3), . . . is arranged at a position from which enough
power to reach a next power feed source is supplied to the moving
body 2A but from which power is difficult to be directly supplied
to each of the power feed destinations 3(1), 3(2), 3(3), . . .
.
[0119] Conversely, each of the plurality of power feed sources
1(1), 1(2), 1(3), . . . is arranged for a distance in which the
moving body 2A can reach a next power feed source by the power
supplied from each of the power feed sources 1(1), 1(2), 1(3), . .
. and at a position where the power is difficult to be directly
supplied to each of the plurality of power feed destinations 3(1),
3(2), 3(3), . . . .
[0120] Each of the power feed sources 1(1), 1(2), 1(3), . . .
basically has the same structure as the power feed source 1 of the
first embodiment shown in FIG. 1. For example, the power feed
source 1(1) includes an AC power source 11(1), a coupling coil
12(1), and a transmission resonance coil 13(1). Each of the power
feed sources 1(2), 1(3), . . . , also includes an AC power source
11, a coupling coil 12, and a transmission resonance coil 13.
[0121] Further, the moving body 2A basically has the same structure
as the moving body 2 shown in FIG. 2.
[0122] Specifically, the moving body 2A includes a relay resonance
coil 21, a coupling coil 22, a rectifier circuit 23, and a drive
motor section 24 to be described later.
[0123] Further, each of the power feed destinations 3(1), 3(2),
3(3), . . . basically has the same structure as the power feed
destination 3 of the first embodiment shown in FIG. 3.
Specifically, each of the power feed destinations 3(1), 3(2), 3(3),
. . . includes a reception resonance coil 31, a coupling coil 32, a
rectifier circuit 33, and a load circuit 34.
[0124] It should be noted that as described above, the power feed
sources 1(1), 1(2), 1(3), . . . are arranged at positions from
which the power is difficult to be directly supplied to the power
feed destinations 3(1), 3(2), 3(3), . . . , respectively.
[0125] Conversely, the power feed destinations 3(1), 3(2), 3(3), .
. . are arranged at positions from which the power is difficult to
be received from the power feed sources 1(1), 1(2), 1(3), . . . ,
respectively, but can be received via the moving body 2A.
[0126] The load circuit 34 of the power feed destination 3 of tae
first embodiment is constituted of the LED driver circuit 341 and
the plurality of LEDs 342, whereas the load circuit 34 of each
power feed destination 3 of the second embodiment is constituted of
an electronic billboard and a driver circuit thereof.
[0127] Moreover, the moving body 2A takes two or several humans
thereon, and by receiving power sequentially from the power feed
sources 1(1), 1(2), 1(3), . . . , drives a drive motor thereof and
travels on the traveling road along which the power feed sources
1(1), 1(2), 1(3), . . . are arranged.
[0128] At this time, the moving body 2A sequentially supplies power
supplied from the power feed sources 1(1), 1(2), 1(3), . . . to
adjacent power feed destinations 3(1), 3(2), 3(3), . . .
respectively, and displays a message on an electronic billboard of
each of the power feed destinations 3(1), 3(2), 3(3), . . . .
[0129] In this case, a message displayed on an electronic billboard
of each of the power feed destinations 3(1), 3(2), 3(3), . . .
includes various types of advertising information and the like.
Use Mode of Noncontact Power Feed System of Second Embodiment
[0130] FIG. 6 is a diagram for explaining a use mode of the
noncontact power feed system according to the second
embodiment.
[0131] As shown in FIG. 6, the moving body 2A picks up a user
(human) and sequentially receives power from the power feed sources
1(1), 1(2), . . . provided on the traveling road. Then, the moving
body 2A supplies the power from the power feed sources 1 to the
power feed destinations 3(1), 3(2), 3(3), . . . to which the moving
body 2A comes close in turns while traveling on the traveling
road.
[0132] Each of the power feed destinations 3(1), 3(2), 3(3), . . .
that receives supply of the power from the moving body 2A displays
a predetermined message on the electronic billboard thereof.
[0133] In a case of an example shown in FIG. 6, the moving body 2A
that has received power from the power feed source 1(1) relays the
power to the adjacent power feed destination 3(1). Accordingly, an
advertising message indicating "Character goods on sale in xx shop"
is displayed on the electronic billboard of the power feed
destination 3(1).
[0134] Then, when the moving body 2A travels by the power from the
power feed source 1(1) and reaches the power feed source 1(2), the
moving body 2A receives power from the power feed source 1(2), and
uses the power to drive the moving body 2A and also relays the
power to the adjacent power feed destination 3(2) from the power
feed source 1(2). Accordingly, an advertising message indicating
"No waiting time in xx attraction" is displayed on the electronic
billboard of the power feed destination 3(2).
[0135] It should be noted that a message displayed on the
electronic billboard of each of the power feed destinations 3(1),
3(2), 3(3), . . . can be delivered in advance from a center side in
a wired or wireless manner, for example.
[0136] In such a manner, the moving body 2A as an automobile
carrying humans moves by being supplied with power from the power
feed sources 1(1), 1(2), 1(3), . . . , and relays and supplies the
power from the power feed sources 1(1), 1(2), 1(3), . . . to the
power feed destinations 3(1), 3(2), 3(3), . . . sequentially.
[0137] Then, it is possible to provide the user on the moving body
2A with a display message that is timely displayed on an adjacent
electronic billboard. Accordingly, it is possible for the user to
obtain latest information and use it as a reference for a next
behavior, and for an information provider to guide the user to a
shop or another amusement attraction.
[0138] It should be noted that in the second embodiment described
above, the case where the display message displayed on the
electronic billboard of each of the power feed destinations 3(1),
3(2), 3(3), . . . is delivered in advance from, for example, a
predetermined center or the like has been described, but the
present invention is not limited thereto.
[0139] For example, in the case of the noncontact power feed system
of the second embodiment, it is also possible to supply a display
message to be displayed on the electronic billboard of the power
feed destination 3 from the power feed source 1 to the power feed
destination 3 via the moving body 2A by using a noncontact power
supply path.
[0140] Hereinafter, there will be described structural examples of
the power feed source 1, the moving body 2A, and the power feed
destination 3 in a case where a display message to be displayed on
an electronic billboard of the power feed destination 3 is supplied
from the power feed source 1 to the power feed destination 3 via
the moving body 2A by using a noncontact power supply path.
[0141] It should be noted that as described above, since each of
the power feed sources 1(1), 1(2), 1(3), . . . has the same
structure, each structure of the power feed sources 1(1), 1(2),
1(3), . . . will be hereinafter described as a structure of a power
feed source 1.
[0142] Similarly, since each of the power feed destinations 3(1),
3(2), 3(3), . . . has the same structure, each structure of the
power feed destinations 3(1), 3(2), 3(3), . . . will be hereinafter
described as a structure of a power feed destination 3.
Structural Example of Power Feed Source 1
[0143] First, a structural example of the power feed source 1 will
be described. FIG. 7 is a diagram for explaining the structural
example of the power feed source 1 of the second embodiment. The
power feed source 1 of the second embodiment transmits a display
message as well as supplying power.
[0144] As shown in FIG. 7, the power feed source 1 of this example
includes a communication section 14 in addition to the AC power
source 11, the coupling coil 12, and the transmission resonance
coil 13. The communication section 14 is connected to the
transmission resonance coil 13 so that the transmission resonance
coil 13 can also be used as a communication antenna.
[0145] If the communication section 14 and the transmission
resonance coil 13 are unconditionally connected to each other,
impedance of the transmission resonance coil 13 is lowered and a Q
factor thereof is also lowered, which causes power feeding
efficiency to be lowered.
[0146] In this regard, in the power feed source 1 of the second
embodiment, a filter circuit 15a is provided between the AC power
source 11 and the coupling coil 12, and a filter circuit 15b is
provided between the communication section 14 and the transmission
resonance coil 13.
[0147] Specifically, as also described above, a frequency band
necessary for power transmission is low, for example, in a range
from several Hz to several tens of Hz. In contrast to this, a
frequency band necessary for information transmission is wider as
information is transmitted at higher speed. In such a case, at
least several kHz is necessary, or several MHz to several GHz may
be necessary in some cases.
[0148] In the second embodiment, it is assumed that a frequency f1
of AC power generated in the AC power source 11 is a value around
10 Hz and a frequency of an information transmission signal that is
generated in the communication section 14 is more than several MHz,
for example.
[0149] In this case, the filter circuit 15b of the power feed
source 1 is designed to have sufficiently high impedance that does
not lower a Q factor of the transmission resonance coil 13 at a
frequency f1. Further, the filter circuit 15a of the power feed
source 1 is designed to have appropriate impedance at which the
coupling coil 12 does not adversely affect wireless communication
at a frequency f2. Here, the appropriate impedance differs
depending on the frequency f2 or a structure of the coupling coil
12.
[0150] Accordingly, in a case where power is fed from the AC power
source 11, impedance of the transmission resonance coil 13 is kept
high and a Q factor thereof is also kept high due to the function
of the filter circuit 15b, with the result that power can be fed
without lowering the power feeding efficiency.
[0151] On the other hand, in a case where information from the
communication section 14 is transmitted, a frequency band of a
signal of the information is set as a high-frequency band of
several MHz or more and impedance is lowered due to the function of
the filter circuit 15b at a time other than at the frequency
f1.
[0152] In other words, the filter circuit 15b keeps impedance high
at the frequency f1, and lowers the impedance other than at the
frequency f1. In this case, a Q factor of the transmission
resonance coil 13 can be lowered and the information signal from
the communication section 14 can be desirably transmitted.
[0153] Accordingly, first, the power feed source 1 can desirably
transmit a high-frequency information signal (display message) via
the communication section 14, the filter circuit 15b, and the
transmission resonance coil 13. After that, the power feed source 1
can transmit (feed) AC power from the AC power source 11 via the
filter circuit 15a, the coupling coil 12, and the transmission
resonance coil 13 without lowering the power feeding
efficiency.
Structural Example of Moving Body 2A
[0154] Next, a structural example of the moving body 2A will be
described. FIG. 8 is a diagram for explaining a structural example
of the moving body 2A of the second embodiment. The moving body 2A
of the second embodiment relays not only power but also an
information signal (display message).
[0155] As shown in FIG. 8, the moving body 2A of this example
includes a communication section 25 and an operation section 26 in
addition to the relay resonance coil 21, the coupling coil 22, the
rectifier circuit 23, and the drive motor section 24. The
communication section 25 is connected to the relay resonance coil
21 so that the relay resonance coil 21 can also be used as a
communication antenna.
[0156] Similar to the case of the power feed source 1 described
above, if the communication section 25 and the relay resonance coil
21 are unconditionally connected to each other, impedance of the
relay resonance coil 21 is lowered and a Q factor thereof is also
lowered, which causes power feeding efficiency to be lowered as in
the case of the power feed source 1 described above.
[0157] In this regard, also in the moving body 2A of the second
embodiment, a filter circuit 27a is provided between the coupling
coil 22 and the rectifier circuit 23, and a filter circuit 27b is
provided between the communication section 25 and the relay
resonance coil 21.
[0158] Then, as in the case of the power feed source 1 described
above, the filter circuit 27b of the moving body 2A is designed to
have sufficiently high impedance that does not lower a Q factor of
the relay resonance coil 21 at a frequency f1. Further, the filter
circuit 27a of the moving body 2A is designed to have appropriate
impedance at which the coupling coil 22 does not adversely affect
the wireless communication at a frequency f2. Here, the appropriate
impedance differs depending on the frequency f2 or a structure of
the coupling coil 22.
[0159] Accordingly, in a case where power is fed from the power
feed source 1 and relayed to a power feed destination, impedance of
the relay resonance coil 21 is kept high and a Q factor thereof is
also kept high due to the function of the filter circuit 27b, with
the result that power can be fed and relayed (transmitted) without
lowering power receiving efficiency or power feeding
efficiency.
[0160] On the other hand, in a case where information from the
power feed source 1 is received or information from the
communication section 25 is transmitted, a frequency band of a
signal of the information is set as a high-frequency band of
several MHz or more, and impedance is lowered due to the function
of the filter circuit 27b at a time other than at the frequency
f1.
[0161] In other words, the filter circuit 27b keeps impedance high
at the frequency f1, and lowers the impedance other than at the
frequency f1. Accordingly, in this case, a Q factor of the relay
resonance coil 21 can be lowered and the information signal can be
desirably transmitted and received.
[0162] Accordingly, first, the moving body 2A receives an
information signal (display message) from the power feed source 1
via the relay resonance coil 21, the filter circuit 27b, and the
communication section 25. Then, the communication section 25 adds
information that is input via the operation section 26 to the
received information signal as necessary, with the result that a
high-frequency information signal can be desirably transmitted to
the power feed destination 3 via the filter circuit 27b and the
relay resonance coil 21.
[0163] After that, the AC power from the power feed source 1 can be
received via the relay resonance coil 21, supplied to the rectifier
circuit 23 via the coupling coil 22 and the filter circuit 27a,
converted into DC power, and then supplied to the drive motor
section 24. At the same time, the AC power from the power feed
source 1 is relayed to the power feed destination 3 via the relay
resonance coil 21 without lowering the power feeding
efficiency.
[0164] It should be noted that the information that is input via
the operation section 26 is, for example, information of a name or
nickname of a user, with which a display message such as "Mr. XX,
xx shop is on sale." that is beneficial for only the user riding on
the moving body 2A can be displayed.
[0165] Further, in a case where the display message has been set in
a power feed destination in advance, the moving body 2A can
transmit the information of the user name or the like that has been
received via the operation section 26, as information that
constitutes part of the display message, to the power feed
destination.
[0166] In other words, the moving body 2A does not only relay the
information signal from the power feed source 1. For example, the
moving body 2A can independently transmit, for example, only an
information signal generated in the moving body 2A based on
information or the like received via the operation section 26 to
the power feed destination 3 via the communication section 25, the
filter circuit 27b, and the relay resonance coil 21.
Structural Example of Power Feed Destination 3
[0167] Next, a structural example of the power feed destination 3
will be described. FIG. 9 is a diagram for explaining a structural
example of the power feed destination 3 of the second embodiment.
The power feed destination 3 of the second embodiment receives not
only power but also relay of a display message via the moving body
2A.
[0168] As shown in FIG. 9, the power feed destination 3 of this
example includes a communication section 35 in addition to the
reception resonance coil 31, the coupling coil 32, the rectifier
circuit 33, and an electronic billboard 34 as a load circuit. The
communication section 35 is connected to the reception resonance
coil 31 so that the reception resonance coil 31 can also be used as
a communication antenna.
[0169] Also in the case of the power feed destination 3, if the
communication section 35 and the reception resonance coil 31 are
unconditionally connected to each other, impedance of the reception
resonance coil 31 is lowered and a Q factor thereof is also
lowered, which causes power receiving efficiency to be lowered as
in the case of the power feed source 1 and moving body 2A described
above.
[0170] In this regard, also in the power feed destination 3 of the
second embodiment, a filter circuit 36a is provided between the
coupling coil 32 and the rectifier circuit 33, and a filter circuit
36b is provided between the communication section 35 and the
reception resonance coil 31.
[0171] Then, as in the case of the power feed source 1 and moving
body 2A described above, the filter circuit 36b of the power feed
destination 3 is designed to have sufficiently high impedance that
does not lower a Q factor of the reception resonance coil 31 at a
frequency f1. Further, the filter circuit 36a of the power feed
destination 3 is designed to have appropriate impedance at which
the coupling coil 32 does not adversely affect the wireless
communication at a frequency f2. Here, the appropriate impedance
differs depending on the frequency f2 or a structure of the
coupling coil 32.
[0172] Accordingly, in a case where power is fed from the moving
body 2A, impedance of the reception resonance coil 31 is kept high
and a Q factor thereof is also kept high due to the function of the
filter circuit 36b, with the result that power can be received
without lowering the power receiving efficiency.
[0173] On the other hand, in a case where information from the
moving body 2A is received, a frequency band of a signal of the
information is set as a high-frequency band of several MHz or more
and impedance is lowered due to the function of the filter circuit
36b at a time other than at the frequency f1.
[0174] In other words, the filter circuit 36b keeps impedance high
at the frequency f1, and lowers the impedance other than at the
frequency f1. Accordingly, in this case, a Q factor of the
reception resonance coil 31 can be lowered and the information
signal can be desirably transmitted and received.
[0175] Accordingly, first, the power feed destination 3 can
smoothly receive an information signal (display message) from the
power feed source 1 that is relayed by the moving body 2A via the
reception resonance coil 31, the filter circuit 36b, and the
communication section 35.
[0176] The communication section 35 extracts a display message from
the received information signal, converts the display message into
an information signal to be supplied to the electronic billboard
34, and then supplies the information signal to the electronic
billboard 34, with the result that the display message can be
displayed on the electronic billboard 34.
[0177] After that, the AC power supplied from the power feed source
1 via the moving body 2A is received via the reception resonance
coil 31, supplied to the rectifier circuit 33 via the coupling coil
32 and the filter circuit 36a, and converted into DC power, with
the result that the DC power can be supplied to the electronic
billboard 34.
[0178] Accordingly, the display message from the power feed source
1 that is relayed and supplied by the moving body 2A is supplied to
the electronic billboard 34, and the electronic billboard 34 is
driven by the power from the power feed source 1 that is relayed
and supplied by the moving body 2A, with the result that the
display message can be displayed.
Effects of Second Embodiment
[0179] The magnetic-field-resonance-type noncontact power feed
system can be applied to a system in which an automobile that moves
while taking humans thereon is used as a moving relay
apparatus.
[0180] Further, the magnetic-field-resonance-type noncontact power
feed system can provide necessary information to users who ride on
the moving body 2A as an automobile at an appropriate timing or
guide the users to a shop or another amusement attraction.
Modified Example of Second Embodiment
[0181] It should be noted that though impedance is adjusted using
the filter circuits in the apparatuses described with reference to
FIGS. 7 to 9, the present invention is not limited thereto. For
example, switching circuits may be provided instead of the filter
circuits.
[0182] For example, in the case of the power feed source 1 shown in
FIG. 7, a switching circuit 16b is provided at the position of the
filter circuit 15b, i.e., between the communication section 14 and
the transmission resonance coil 13. Further, a switching circuit
16a is provided at the position of the filter circuit 15a, i.e.,
between the AC power source 11 and the coupling coil 12.
[0183] Then, the switching circuit 16a is turned on and the
switching circuit 16b is turned off when power is fed. Accordingly,
impedance of the transmission resonance coil 13 can be kept high
and power from the AC power source can be fed efficiently.
[0184] In addition, the switching circuit 16a is turned off and the
switching circuit 16b is turned on when communication is performed.
Accordingly, the information signal from the communication section
14 can be appropriately transmitted via the transmission resonance
coil 13.
[0185] As described above, the switching circuits may be provided
instead of the filter circuits and switched when power is fed and
communication is performed. It should be noted that also in the
moving body 2A and the power feed destination 3, switching circuits
may be similarly provided to a communication system and a power
feed system and switched when communication is performed and power
is fed (received).
[0186] Further, in the examples described with reference to FIGS. 7
to 9, the transmission resonance coil 13, the relay resonance coil
21, and the reception resonance coil 31 are also used as the
communication antenna, and the supply of the power and the supply
of the information signal are performed using the same path as much
as possible.
[0187] However, the present invention is not limited to the above
case. Since the information signal can be transmitted with a
relatively small amount of power and a large amount of information
can be transmitted at high-speed, an antenna designated for
communication may of course be provided.
[0188] Specifically, in the case of the power feed source 1 shown
in FIG. 7, the communication section 14 is connected to not the
transmission resonance coil 13 but a communication antenna that is
newly provided. Further, in the case of the moving body 2A shown in
FIG. 8, the communication section 25 is connected to not the relay
resonance coil 21 but a communication antenna that is newly
provided. Furthermore, in the case of the power feed destination 3
shown in FIG. 9, the communication section 35 is connected to not
the reception resonance coil 31 but a communication antenna that is
newly provided.
[0189] With this structure, the communication system and the power
feed system may be separated and independently transmit/receive
information signals and power, respectively. In this case, since
the transmission/reception of information signals and the
transmission/reception of power can be performed at the same time,
the effect that the transmission/reception of information signals
is easily controlled, or the like can be produced.
[0190] Further, in the case of the noncontact power feed system of
the second embodiment, the moving body 2A also receives supply of
power from the power feed source 1, but the present invention is
not limited thereto. For example, the moving body 2A may be
equipped with a drive battery and travel by power from the drive
battery.
[0191] In addition, the moving body 2A may include an AC power
source and feed the power generated in the moving body 2A (AC
power) to a power feed destination. That is, the moving body 2A can
be given a function as the power feed source 1.
Application to Method of the Present Invention
[0192] The noncontact power feed method in the noncontact power
feed system described with reference to FIGS. 1 to 9 is one of
noncontact power feed methods of the present invention. Further,
the noncontact power feed method for the moving bodies 2 and 2A
descried with reference to FIGS. 3 and 8 is one of the noncontact
power feed methods of the present invention. Moreover, the
noncontact power feed method for the power feed destination
descried with reference to FIGS. 4 and 9 is one of the noncontact
power feed methods of the present invention.
Others
[0193] It should be noted that though the moving bodies 2 and 2A
have been described as one having an automobile shape or as an
automobile in the embodiments described above, but the present
invention is not limited thereto. Moving bodies of various modes
such as a hull-type moving body that moves on the water, an
airplane-type moving body that flies in the air, and an
elevator-type moving body that vertically moves can be structured
and used.
[0194] Further, the power feed destination has been described as
one using a light-emitting device and a display device, such as an
LED and an electronic billboard in the embodiment described above,
but the present invention is not limited thereto. As the load
circuit of the power feed destination that receives supply of the
power from a moving body, various circuits such as a circuit for
generating/releasing sound, an oscillation circuit, and a
photographing circuit can be used.
[0195] Moreover, the case where power is supplied in a noncontact
manner by a magnetic field resonance system has been described in
the embodiments described above, but the present invention can be
similarly applied to a case where power is supplied in a noncontact
manner by using not only the magnetic field resonance system but
also an electric field resonance system and an electromagnetic
resonance system.
[0196] In addition, the power feed source is provided with the
coupling coil (coupling device) between the AC power source and the
transmission resonance coil in the embodiments described above.
Further, the moving body is provided with the coupling coil
(coupling device) between the relay resonance coil and the
rectifier circuit. Furthermore, the power feed destination is
provided with the coupling coil (coupling device) between the
reception resonance coil and the rectifier circuit.
[0197] However, the present invention is not limited to the above
case, and can be structured without using the above coupling coils
(coupling devices) as long as the reflection of power or the
problems of impedance can be suppressed.
[0198] The present application contains subject matter related to
that disclosed in Japanese Priority Patent Application JP
2009-171797 filed in the Japan Patent Office on Jul. 23, 2009, the
entire content of which is hereby incorporated by reference.
[0199] It should be understood by those skilled in the art that
various modifications, combinations, sub-combinations and
alterations may occur depending on design requirements and other
factors insofar as they are within the scope of the appended claims
or the equivalents thereof.
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